SAO PAULO (Reuters) - Private equity firms Warburg Pincus and Gavea Investimentos are planning an initial public offering by Grupo GPS, a Brazilian facilities services provider in which they are key stakeholders, two sources familiar with the matter said. Part of the proceeds of the offering, which are expected to reach 3 billion reais ($537.44 million), will go to the two private equity firms, with the rest going to the company for possible investment purposes, one of the sources added. The company has hired investment banking units of Goldman Sachs GS.N, Itau Unibanco ITUB4.SA, BTG Pactual BPAC11.SA, Citigroup Inc C.N, Morgan Stanley MS.N and Bank of America Corp BAC.N to manage the IPO, according to the sources. ADVERTISEMENT Founded in 1962, GPS has more than 86,000 employees and 2,400 clients, according to its website. It provides services such as cleaning, security, logistics and catering for companies. If successfully listed, GPS will be the first facilities company listed on Brazil’s stock exchange, B3 SA. Warburg Pincus and Gavea acquired minority stakes in GPS in 2015 and 2017, respectively. The company, which has bought up a series of smaller rivals, consolidating an extremely fragmented sector, posted net income of 192 million reais last year. GPS would be the third Brazilian company in which Warburg Pincus has a stake to go public this year, following pet store chain Petz PETZ3.SA and logistics company Sequoia Solucoes Logisticas SEQL3.SA, whose IPO is expected to price later on Monday. Reporting by Carolina Mandl in Sao Paulo; Editing by Matthew Lewis