Question: What is the name of the private equity firm that owns the Equity Office?

Context paragraphs:
Leeds Equity Partners: Leeds Equity Partners is a private equity firm focused on investments in the Knowledge Industries.  The firm is investing its fifth private equity fund, Leeds Equity Partners V, L.P., the largest fund focused exclusively on investing in this sector.  The firm's investors include a broad range of leading institutions, public and private pension plans, endowments, foundations, financial institutions, family offices and high-net-worth individuals.

Rede Partners: Rede Partners is an independent private equity fundraising advisory firm focused on primary fundraising, secondaries, strategic advisory projects and investor relations advisory.  The firm is based in London with a team of 21 professionals.  Rede Partners was founded in 2011 by Scott Church and Adam Turtle.  Scott's career began at Merrill Lynch where he remained for sixteen years, ending it as a Managing Director within the private equity group (placement).  He moved to Lazard where he was a Managing Director in the private funds group.  Adam's, previously a Director within the investor relations group at private equity firm Actis, began his career with Credit Suisse's private fund placement group.

Lincolnshire Management: Lincolnshire Management is a private equity firm focused on investments and acquisitions in middle-market companies across a range of industries.  In 2010, Private Equity News ranked Lincolnshire as a top ten performing private equity firm.  Additionally, In 2011, CNN Money /Fortune Magazine ranked Lincolnshire Management as the 5th ranked private equity firm.

Thomas H. Lee (businessman): Thomas H. Lee (born March 27, 1944) is an American businessperson, financier and investor and is credited with being one of the early pioneers in private equity and specifically leveraged buyouts. Thomas H. Lee Partners (THL), the firm he founded in 1974, is among the oldest and largest private equity firms globally.  Lee is currently the managing partner of Lee Equity Partners, a private equity firm he founded in 2006 after leaving Thomas H. Lee Partners.

The Blackstone Group: The Blackstone Group L.P. is an American multinational private equity, alternative asset management and financial services firm based in New York City.  As the largest alternative investment firm in the world, Blackstone specializes in private equity, credit and hedge fund investment strategies.

Kohlberg Kravis Roberts: KKR & Co.  L.P. (formerly known as Kohlberg Kravis Roberts & Co.) is an American multinational private equity firm, specializing in leveraged buyouts, headquartered in New York City.  The firm sponsors and manages private equity investment funds.  The firm has completed over $400 billion of private equity transactions since its inception.

Apax Partners: Apax Partners LLP is a British private equity and venture capital firm, headquartered in London, England.  The company also operates out of eight other offices in New York, Hong Kong, Mumbai, Tel Aviv, Madrid, Stockholm, Milan and Munich.  The firm, including its various predecessors, have raised approximately $35 billion (USD) dating back to 1969.  Apax Partners is one of the oldest and largest private equity firms operating on an international basis, ranked the seventh largest private equity firm globally.

Mekong Capital: Mekong Capital is a Vietnam-focused private equity firm.  Operating in Vietnam since 2001, Mekong Capital is one of the first private equity firms to engage Vietnam, and has completed 30 private equity investments in Vietnam through 4 funds with approximately 25 full-time employees.  Mekong Capital has offices in Ho Chi Minh City, Hanoi.  Focusing on manufacturing companies until 2005, Mekong Capital shifted its focus towards consumer-driven businesses in 2006.  Mekong Capital is known as a private equity firm that has invested significant resources in the development of its corporate culture, and in the corporate cultures of its portfolio companies, and is the subject of several case studies.

EnCap Investments: EnCap Investments is an American private equity firm, specializing in the oil & gas industry.  The firm was established in 1988 and is based in Houston, Texas.  According to an updated 2013 ranking created by industry magazine Private Equity International (published by PEI Media called the PEI 300), the firm's rank is #16 with some $11.8 billion under management, based on the amount of private equity direct-investment capital raised over a five-year window.

Equity Office: Equity Office is the owner of 50 million square feet of office space.  The company is owned by funds managed by The Blackstone Group.

Supporting paragraphs: Equity Office The Blackstone Group
Answer: The Blackstone Group