(Bloomberg) — Some of China’s biggest state-owned banks have been invited to pitch for the Saudi Aramco initial public offering, people with knowledge of the matter said, signaling the oil giant’s potential desire to attract Asian investors to the $100 billion listing.

Investment banking units of Industrial & Commercial Bank of China Ltd. and Bank of China Ltd. are among firms competing for a role on the offering, the people said, asking not to be identified because the information is private. Senior management of some Chinese banks visited Saudi Arabia multiple times this year before Aramco officially requested proposals, one of the the people said.

A number of Asia-based dealmakers have been cutting short their vacations to finish work on the pitches, according to the people. Aramco has asked most banks to submit proposals by next week, the people said. It invited more than 20 advisory firms from the U.S., Europe and Asia to compete for a role on the offering, including some of the world’s biggest underwriters as well as a number of smaller banks, one person said.

While Aramco hasn’t made a final decision on its international listing destination, the oil giant’s outreach to large Chinese banks is an indication it’s seriously considering the possibility of selling shares in Hong Kong, according to the people. Top officials from the exchanges in London, New York and and Hong Kong have been actively pitching the oil giant in recent weeks, Bloomberg News has reported.

Aramco didn’t immediately respond to a request for comment outside of regular business hours. A representatives for ICBC’s investment banking unit declined to comment, while representatives at BOC’s overseas advisory arm and ICBC’s Beijing headquarters couldn’t immediately be reached for comment.

ICBC, the world’s largest lender by assets, has participated in some of Aramco’s past project financings, one person with knowledge of the matter said. It’s the only one of China’s big four state-owned banks to have a commercial banking presence in the Saudi capital of Riyadh, where it has one branch, according to the lenders’ annual reports.

Bank of China’s London branch was a co-manager on Aramco’s $12 billion debut bond sale in April, making it the only Chinese bank that worked on the blockbuster deal that attracted more than $100 billion of investor orders.

Chinese-backed investment banks have been increasingly dominating the Hong Kong league tables and accounted for 7 of the 10 most active IPO arrangers in the city this year, according to data compiled by Bloomberg. ICBC was the 6th busiest bank with a 4.3% market share, while Bank of China ranks 14th, the data show.

–With assistance from Alfred Liu, Carol Zhong and Matthew Martin.