Chelsea have agreed a deal to sign the teenage Anderlecht striker Romelu Lukaku.

The 18-year-old will join the Premier League side, subject to passing a medical and agreeing personal terms.

Anderlecht announced the sale of Lukaku on their website, but did not reveal the fee. Chelsea reportedly had an £18m bid turned down last month.

"He's an interesting young prospect," said boss Andre Villas-Boas after Chelsea's win over Rangers on Saturday.

"The situation is now that we have to position ourselves to maybe get this kind of talent."

Lukaku became a household name in Belgium when he was top scorer in the domestic league in the 2009-2010 season aged 16.

"It's a shame we have to let go of Romelu, who was scouted and trained by Anderlecht, but the transfer is a win-win situation for the player and the club," said Anderlecht manager Herman van Holsbeeck.

It comes as winger Yury Zhirkov, 27, left Chelsea for Russian side Anzhi Makhachkala.

No details have been released on the Zhirkov transfer fee either but reports in Russian suggest it will be £13.2m.

The 27-year-old, who joined Chelsea from CSKA Moscow two years ago, has signed a four-year contract with Anzhi.

Zhirkov, who joined Chelsea for £18m and has made 49 appearances for the club, was presented to the crowd before Anzhi's home league match against Tom Tomsk on Saturday.

"I'm very happy to be here in Makhachkala," he told supporters.

"I hope to make my Anzhi debut in our next game against Spartak Moscow [next Sunday]."

But despite the presentation, Chelsea boss Andre Villas-Boas said the deal was not yet complete.

He said: "Yury is in between reaching a full agreement, between club and player, with Anzhi and in the end it was mostly his decision.

"It is a great financial offer for him, it is a return home and I think he has decided to part company."