Jan 6 (Reuters) - Parcel locker company InPost said on Tuesday that it had received an indicative takeover proposal from an unnamed party, sending its share price sharply higher.

InPost gave no details on the price and said there was no assurance that the proposal would lead to a transaction.

The company's spokesperson declined to comment. It had not previously publicly indicated that it was looking for a buyer.

Sky News later reported that a consortium including private equity firm Advent International was behind a 6 billion euro ($7 billion) approach to take InPost private.

Advent declined to comment.

InPost's Amsterdam-listed shares had jumped 23% to a six-month high by 1347 GMT, on track for their biggest one-day rise on record and bringing its market value to around 7 billion euros. 

The company's shares also rose 11% in high volumes on Monday. They lost around 37% last year and hit a two-year low in November in part due to worries over its biggest customer in Poland decreasing its dependency on InPost for deliveries.

Advent bought a majority stake in InPost in 2017 but has since reduced it and now owns 6.5%, according to InPost website.

InPost said it had formed a special committee of supervisory and management board members that will "carefully consider all aspects of a potential transaction, ensuring that the interests of the company and all of its stakeholders are taken into account".

PARCEL LOCKER EXPANSION

InPost's biggest shareholder is Czech investment firm PPF Group with a 28.75% stake, according to InPost's website.

PPF declined to comment.

InPost's CEO and founder Polish billionaire Rafal Brzoska's company A&R Investments has a 12.49% stake.

InPost, which operates across nine countries including its home market Poland, has one of the largest European networks of automated parcel machines, or APMs.

It has been accelerating its roll-out abroad as competition in its home country intensifies and made a string of deals last year, including buying Yodel in Britain and a Spanish delivery company.

JPMorgan analysts said in a note that they thought the most credible interest was likely to be from private equity.

"We see InPost's European structural growth strategy as misunderstood by the market and...we see the current depressed valuation as attracting increased investor questions around InPost's ownership structure," they added.

($1 = 0.8523 euros)

($1 = 0.8539 euros)

(Reporting by Anna Pruchnicka, additional reporting by Jason Hovet, Editing by Jan Harvey, Matt Scuffham and Kirsten Donovan)

By Anna Pruchnicka