March 12 (Reuters) - U.S Senator Elizabeth Warren of

Massachusetts is asking Amazon ( AMZN ) CEO Andy Jazzy to

provide details on its algorithmic pricing and contracting

practices for the company's procurement platform after an

advocacy group said some schools and local governments paid more

for office supplies compared to others in nearby locations,

according to a letter seen by Reuters.

* "Instead of offering fixed prices for all buyers, which

are typical in the procurement space, Amazon Business subjects

buyers to algorithm-driven dynamic pricing that forces school

districts and local governments to pay ever-changing, often

inflated costs for essential goods," Sen. Warren said in the

letter.

* States including California and New York, along with the

U.S. Federal Trade Commission, have raised concerns about the

collection and use of personal data to determine prices

* Advocacy group Institute for Local Self-Reliance in

December released a report saying algorithmic pricing by Amazon

Business lets the company covertly raise prices.

* One city paid three times as much for a pack of Sharpies

as another nearby school district, according to the ILSR

report.

* Warren asked Amazon ( AMZN ) a dozen questions about how it

determines prices for local governments and school districts,

and its use of personal consumer data to set prices.

* Warren in February sent a letter to Amazon ( AMZN ) on behalf of

the Committee on Banking, Housing, and Urban Affairs requesting

information about tariff-induced price increases on its

e-commerce marketplace and if the company plans to decrease

prices if it receives refunds for tariff payments recently

deemed illegal by the US Supreme Court.